levels set to meet their own domestic
demand requirements with additional
quantities available for export. Many
developing nations tend to develop their
agricultural resources first to feed their
population.  Development of easily
extractable mineral resources follows with
salt being one of the first commodities to
be mined. Some countries, such as the
United States, import a substantial
amount of salt to meet total demand
requirements because of economic
factors.
Capacity.-Each type of salt produced
in the world has unique mining,
processing, and marketing characteristics
that determine the criteria for deriving
rated capacities.  Rated capacity is
defined as the maximum quantity of
product that can be produced in a period
of time on a normally sustainable long-
term operating rate, based on the physical
equipment of the plant, and given
acceptable routine operating procedures
involving labor, energy, materials, and
maintenance. Capacity includes both
operating plants and plants temporarily
closed that, in the judgement of the
author, can be brought into production
within a short period of time with
minimum capital expenditure. Capacity
data were derived from industry sources,
published reports, and estimates based on
production trends.
Rock.-Because the majority of rock
salt was used for deicing, the operating
rate of rock salt facilities fluctuated with
the demand for deicing salt, again
dependent on the severity of winter
weather conditions. During periods of
strong demand, production levels often
achieve, or exceed in certain situations,
the rated capacities. Full mine capacity
generally is a function of the hoisting
capabilities of the mines. Assuming that
the workweek is 5 days (250 workdays
per year), two working shifts and one
maintenance shift per day, and at least
one short-term planned turnaround for the
mine and mill per year, the production
capacities for domestic rock salt
operations in 1993 was 16 million tons
(17 million short tons).


Solar.-Solar salt, also known as
marine and sea salt, is obtained from the
solar evaporation of seawater, of
landlocked bodies of saline water, and of
discharged brines. Because evaporation
rates must exceed the precipitation rates,
the climatic conditions and geographic
locations of solar evaporation facilities
are critical to the successful production
and harvesting of solar salt. Therefore,
rated capacities generally are based on the
historical evaporation patterns within a
region and vary depending on the location
and the surface areas of the evaporation
ponds.   Only unpredictable seasonal
precipitation and market conditions
usually affect the production, and market
conditions usually affect the production
rates of the facilities.  In 1993, total
domestic solar salt production capacity
was 3.95 million tons (4.35 million short
tons).
Vacuum Pan.-The mechanical
evaporation of salt by the vacuum pan
process is dependent on the number and
size of the vacuum crystallizers operating
in series. Rated capacities are usually
easier to establish because of the proven
design performance of the equipment.
The total production capacity of the
domestic vacuum pan salt producers in
1993 was 4.30 million tons (4.74 million
short tons).
Brine.-Brine capacities are difficult
to derive because they are based on the
variabilities of the injection rate of the
solvent and the solubility rates of the
underground salt bodies. Both determine
the quantity of brine produced.  in
addition, production levels are dependent
on the demand for the products that the
brine is being used to manufacture.
Therefore, brine production capacity is
assumed to be equal to the quantity of
brine produced annually. Although data
cannot be published for individual
companies, the aggregate domestic brine
production capacity in 1993 was 18.04
million tons (19.88 million short tons),
which was the total quantity of salt brine
produced.


OUTLOOK


The outlook for salt for the near future
is optimistic. The drawdown of rock salt
inventories late in 1993 will cause
producers to increase production during
early  1994   to meet the demand      for
deicing salt.   Any additional supplies
required would have to be imported.
Sales of solar salt and rock salt from
domestic or import sources for chloralkali
manufacture may be injeopardy, pending
the outcome of any proposed legislation
to reduce or eliminate the use of chlorine.
Despite the adverse publicity regarding
chlorine in the environment, chlorine
production should be strong since about
18 % of total chlorine output is exported
as   derivatives,   such    as   ethylene
dichloride, vinyl chloride monomer, and
PVC. In addition, domestic demand for
these commodities is estimated to grow at
5 % per year for the next few years
despite the decline in the use of chlorine
in pulp bleaching.
'Can We Afford To Ba Chlorine? Charles River
Associates, Sept 1993, 4 pp.
21he Washington Post EPA Seeks Strict Paper-
Industry Rules Aimed at Cutting Dioxin, Air Pollution. V.
222, No. 87, Nov. 2, 1993, p. A24.
3Chemical Week. Chlorine Ban Proposed. V. 153, No.
6, p. 38.
4   -. RRecycling Order Omits Chlorine Ban. V.
153, No. 15, p. 6.
Formosa Worries Chlor-alkali Players. V.
152, No. 25, p. 15.
6   -. HoltahemAcuires LCP Chlor-alkaliUnits
With Allied Signal's Help. V. 153, No. 15, p. 16.
OTHER SOURCES OF INFORMATION
Bureau of Mines Publications
Salt. Ch. in Minerals Yearbook, annual.
Salt.     Ch.  in   Mineral  Commodity
Summaries.
Directory of Companies Producing Salt in
the United States, in annual Mineral
Industry Surveys.
Salt.  Ch. in 1985 Mineral Facts and
Problems.
The Material Flow of Salt, IC 9343, 1993,
32 pp.
Other Sources
Canadian Minerals Yearbook, Chapter on


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